Patents by Inventor Yiqi Yang

Yiqi Yang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6036726
    Abstract: A process for recycling colored polyamide material comprises the steps of (a) contacting solid colored polyamide material with an organic solvent composition at a temperature effective to dissolve the polyamide, thereby forming a solution containing colorant and dissolved polyamide; and (b) separating colorant from the polyamide. The process can optionally further comprise the step of recovering the colorant, recovering the polyamide, or recovering both the polymer and colorant. The organic solvent composition preferably is selected from the group consisting of aliphatic and aromatic ketones, aliphatic and aromatic alcohols, diols, water, and combinations thereof. Solvent compositions comprising at least one alcohol selected from the group consisting of butanediol, butanol, ethanol, and benzyl alcohol are preferred, such as aqueous solutions of 1-butanol or ethanol.
    Type: Grant
    Filed: February 6, 1998
    Date of Patent: March 14, 2000
    Assignee: Solutia Inc.
    Inventors: Yiqi Yang, Le Moyne W. Plischke, George R. McLellan, Jerauld L. Dickerson
  • Patent number: 5846787
    Abstract: Disclosed are processes for pretreating cellulosic materials in liquid water by heating the materials in liquid water at a temperature at or above their glass transition temperature but not substantially exceeding 220.degree. C., while maintaining the pH of the reaction medium in a range that avoids substantial autohydrolysis of the cellulosic materials. Such pretreatments minimize chemical changes to the cellulose while leading to physical changes which substantially increase susceptibility to hydrolysis in the presence of cellulase.
    Type: Grant
    Filed: July 11, 1994
    Date of Patent: December 8, 1998
    Assignee: Purdue Research Foundation Office of Technology Transfer
    Inventors: Michael R. Ladisch, Karen L. Kohlman, Paul L. Westgate, Joseph R. Weil, Yiqi Yang
  • Patent number: 5296269
    Abstract: An improved silk textile is described which exhibits more desirable wet wrinkle-recovery and tear strength than untreated silk. The silk textile contains polycarboxylic acid cross-links which are relatively strong and resistant to hydrolysis.A process for manufacturing an improved silk textile is presented which includes wetting an untreated silk textile with a specially formulated finishing agent. The finishing agent includes polycarboxylic acid, a catalyst, and a swelling agent. The wetted silk textile is dried and cured at an elevated temperature.
    Type: Grant
    Filed: March 3, 1993
    Date of Patent: March 22, 1994
    Assignee: The Board of Trustees of the University of Illinois
    Inventors: Yiqi Yang, Shiqi Li